I personally don't think it'd help some of these people, especially older ones who might've been predatory for years.

Counselling might help to make them see how wrong their thoughts and actions are, but I doubt it'd take away their desire to carry out their fantasies. The only way round it's to physically castrate these men, therefore removing their sexual desires altogether.

I read that once a man's been castrated, his sexual desires're leave him, although it can just lead to a diminished one. I think in general it works. Think of all those eunuchs that were allowed into harems to act as servants and guards for the females. If they'd still been capable of sexual desires, they'd have had a field day! : )